Thanks for posting this Ruth-
A few years back, I had posted about the parasite of the nematodes-Catenaria anguillulae.
The post seems to be missing but I kept it in total. Had
one response per below.
For those with Lyme- (the given being the nematodes) -added to the facts about the chytrids ,
found when searching for the -parasitic pine pollen grains-
it ties it up quite nicely.
Catenaria a parasite of nematodes
« Thread Started on Nov 9, 2005, 10:30pm »
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helios.bto.ed.ac.uk/bto/microbes/catenar.htm#TopFair use
The Microbial World:
Catenaria anguillulae, a parasite of nematodes
Produced by Jim Deacon
Institute of Cell and Molecular Biology, The University of Edinburgh
Catenaria anguillulae
Catenaria anguillulae is a member of the Chytridiomycota, the only
major group of
true (chitin-walled) fungi that produce motile spores, termed
zoospores. This fungus
can be grown easily on culture media but in nature it is often found
as a facultative
(non-specialised) parasite of nematodes, the eggs of liver flukes, or
other small
organisms. The images below were taken from videotapes, using phase-contrast
microscopy, and show the behaviour of this fungus when parasitising nematodes.
A. Three zoospores, each with a single posterior flagellum. The
zoospore on the left
shows a conspicuous nuclear cap (see pointer) which contains ribosomes
and is located
above the nucleus (seen as a lighter body which extends to the base of the
flagellum). Ordinarily it would not be possible to see the flagellum
because it beats
rapidly, but these zoospores have stopped swimming and are crawling
across a glass
surface (amoeboid crawling). Two of the zoospores show conspicuous pseudopodia,
marked by arrowheads
B. Two zoospores crawling along the surface of a nematode; the
flagella are clearly
seen (arrowhead).
C. Five zoospores (the centre one is out of focus) that were attracted
to a specific
site on the nematode - the bulb region (heart-shaped) where an
excretory pore (not
seen) discharges compounds that cause zoospores to accumulate by
chemotaxis. One of
the zoospores recently arrived at this site and we can still see its flagellum
(arrowhead); the other zoospores have encysted and withdrawn their flagella.
D. Three zoospore cysts (marked 'c') that germinated on a glass surface. Each
produced a narrow outgrowth tube which swelled to form a vesicle
(ves), and narrow
rhizoids (rh) developed from the vesicles. Lipid bodies are seen as
bright globular
structures in the vesicles and some of the cysts.
E. Several zoospores were attracted to the tail region of a nematode,
near the anal
pore (not seen). They encysted and produced vesicles and rhizoids,
many of which are
inside the body of the animal. At a later stage of development, the
vesicles will
become sporangia: their contents will be cleaved to produce zoospores
which will be
released to repeat the infection cycle.
For further aspects of Catenaria zoospore biology see Chytrid zoospores
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Sidney
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Re: Catenaria a parasite of nematodes
« Reply #1 on Nov 10, 2005, 10:04pm »
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www.google.com/search?hl=en&ie=ISO-8859-1&q=Chytrids+%2B+frog+deformitiesThanks for this, Jill.
Chytrids are linked to death and deformaties in frogs and created a
big buzz among
the scientific community a few years ago since it seemed to be
happening world-wide.